European Workshop on Chemistry - EWPC 15/2018 March 14-16

ORAL PRESENTATIONS

Uppsala University, SWEDEN European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Bridged Triarylphosphines as Versatile Platforms for the Construction of Polycyclic Heteroaromatic Compounds

Milan Kivala,a,* Johannes Ascherl,a Tobias A. Schauba,b and Frank Hampela

aDepartment of Chemistry and Pharmacy, University of Erlangen-Nürnberg. Erlangen. Germany. bDepartment of Chemistry and Biochemistry, University of Oregon. Eugene. Oregon. USA. [email protected]

The incorporation of heteroatoms directly into the sp2-carbon skeleton of polycyclic aromatic hydrocarbons (PAHs) provides a powerful tool – next to variation of their size and periphery and/or lateral decoration with various substituents – to manipulate their optoelectronic properties and supramolecular behavior.1,2 This is particularly relevant in the context of organic electronics for which -conjugated organic materials finely tuned in terms of their photophysical, redox, and self-assembly properties are of high demand. Rather surprisingly, the field of phosphorus-containing PAHs is still in its infancy, although such compounds often show strikingly different properties from their - containing counterparts such as the unique pyramidal geometry and the Lewis basicity of the phosphorus centre, providing for additional chemistry.3

We have recently identified various relatively simple bridged triarylphosphine derivatives as versatile building blocks for the construction of unprecedented phosphorus-containing PAHs.4 This contribution will address our respective synthetic efforts and the fundamental characteristics of the resulting compounds.

Acknowledgement This work was supported by the Deutsche Forschungsgemeinschaft (DFG) as part of SFB 953 “Synthetic Carbon Allotropes” and the “Solar Technologies Go Hybrid” (SolTech) initiative of the Free State of Bavaria. References 1 P. O. Dral, M. Kivala, T. Clark, J. Org. Chem. 2013, 78, 1894–1902. 2 M. Stępień, E. Gońka, M. Żyła, N. Sprutta, Chem. Rev. 2017, 117, 3479–3716. 3 T. Baumgartner, Acc. Chem. Res. 2014, 47, 1613–1622. 4 a) T. A. Schaub, E. M. Zolnhofer, D. P. Halter, T. E. Shubina, F. Hampel, K. Meyer, M. Kivala, Angew. Chem. Int. Ed. 2016, 55, 13597–13601; b) T. A. Schaub, R. Sure, F. Hampel, S. Grimme, M. Kivala, Chem. Eur. J. 2017, 23, 5687–5691; c) T. A. Schaub, S. M. Brülls, P. O. Dral, F. Hampel, H. Maid, M. Kivala, Chem. Eur. J. 2017, 23, 6988–6992.

Uppsala University, SWEDEN KL1 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Expanding the Net: Novel π-Extended Materials Based on Six- Membered Phosphorus Heterocycles

C. Romero-Nieto*

Organisch-Chemisches Institut, Heidelberg University. Heidelberg. Germany. [email protected]

-Extended organic architectures are a fascinating class of compounds that plays a fundamental role in the materials science. The efficient overlap of atomic orbitals along an extended net of polyaromatic systems enables outstanding properties such as strong luminescence and high charge mobilities. An efficient strategy to modulate the latter optoelectronic properties consists in embedding heteroatoms into the carbon scaffold. To that end, phosphorus atoms are particular interesting; e.g. they present an electron lone pair that is readily available for a variety of reversible post-functionalization reactions. As a matter of fact, we recently reported novel phosphorus- containing phenalenes whose optoelectronic properties (emission color, fluorescence quantum yield up to 0.8 and ambipolar redox properties) could be efficiently modulated by phosphorus post- functionalization.1

In this communication, I will report the synthesis of a new generation of π-extended architectures based on six-membered phosphorus heterocycles.2 Furthermore, I will present a detailed investigation of their structural and optoelectronic properties. All in all, I will describe the benefits of embedding six-membered phosphorus heterocycles into π-extended polyaromatic hydrocarbons. The new materials overcome the performances of our previously reported phosphaphenalenes; they exhibit, among others, remarkable electron-accepting properties and fluorescence quantum yields of up to 0.85.2

References 1 a) C. Romero-Nieto, A. López-Andarias, C. Egler-Lucas, F. Gebert, J.-P. Neus, O. Pilgram, Angew. Chem. Int. Ed. 2015, 54, 15872-15875; b) P. Hindenberg, A. López-Andarias, F. Rominger, A. De Cózar, C. Romero- Nieto, Chem. Eur. J. 2017, 23, 13919-13928; c) O. Larranaga, C. Romero-Nieto, A. De Cózar, Chem. Eur. J. 2017, DOI: 10.1002/chem.201703495. 2 a) P. Hindenberg, M. Busch, A. Paul, M. Bernhardt, P. Gemessy, F. Rominger ,C. Romero-Nieto, Submitted.

Uppsala University, SWEDEN KL2 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Lewis Adducts of the Parent Phosphine, PH3 A Crystallographic and Spectroscopic Study

Matthew Baker, Mark Bispinghoff, and Hansjörg Grützmacher *

Laboratory of Inorganic Chemistry, ETH Zürich. Vladimir-Prelog-Weg 1, 8093 Zürich. Switzerland. [email protected]

1 The first Lewis Adduct of phosphane, BCl3·PH3, was reported in 1890. Further reports have since discussed enthalpy of formation,2 vibration spectra,3 11B NMR spectra,4 and 1H NMR spectra.5 However, an overview of these adducts and their properties, including crystal structures and 31P NMR spectra, remains absent from the literature.

The crystal structures and NMR spectra of compounds of the type EX3·PH3 (E = B, Al, Ga, In and X = Cl, Br, I) will be discussed in detail.

31 Figure 2 Structure of BI3·PH3 Figure 2 P spectrum of BI3·PH3

Acknowledgement The authors gratefully acknowledge ETH for their financial support.

References 1 A. Besson, C. R. Acad. Sci., Paris, 1890, 110, 516-518 2 R. Höltje, Z. Anorg. Allg. Chem., 1933, 209, 241-248 3 a) P. A. Tierney, D. W. Lewis, D. Berg, J. Inorg. Nucl. Chem., 1962, 24, 1163-1169 b) J. E. Drake, J. L. Hencher, B. Rapp, J. Chem. Soc., Dalton Trans., 1974, 595-603 c) M. J. Taylor, S. Riethmiller, J. Raman Spect., 1974, 15, 370-376 4 J. D. Odom, S. Riethmiller, J. D. Witt, J. R. Durig, Inorg, Chem., 1973, 1123-1127 b) J. E. Drake, B. Rapp, J. Inorg. Nucl. Chem., 1974, 36, 2613-2615 5 J. E. Drake, J. Simpson, J. Chem. Soc. A., 1968, 974-979

Uppsala University, SWEDEN O1 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

[P(µ-NBbp)]2 - a PN biradicaloid synthesized from an acyclic precursor

Lilian Sophie Szych1, Ronald Wustrack1, Jonas Bresien1, Axel Schulz1,2, Alexander Villinger1 [email protected], [email protected] 1Institut für Chemie, Abteilung Anorganische Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany. 2Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, 18059 Rostock, Germany.

Group 15 open shell singlet biradicaloids of the type [P(µ-NR)]2 show an interesting and diverse reaction behaviour, for example towards molecules bearing multiple bonds or when it comes to the activation of small molecules. They are usually synthesized by the reduction of chlorinated cycles of the type [ClP(µ-NR)]2. R is a sterically demanding substituent which ensures the kinetic stabilization of the reactive biradicaloid (Scheme 1).[1,2]

Scheme 1. Top: Reduction of the Bbp stabilized derivatives, leading to the biradicaloid. Bottom: Molecular structures of A, B, C; orange: phosphorus; blue: nitrogen; green: chlorine.

We are currently investigating the synthesis and reaction behaviour of a new biradicaloid, stabilized [3] with the Bbp substituent (2,6-bis[bis(trimethylsilyl)methyl]phenyl). Reducing the [ClP(µ-NR)]2 heterocycle using the “classical route”, we could indeed synthesize the desired biradical B. However, the reduction of the acyclic compound Bbp-N(PCl2)2 also leads to the biradicaliod, which represents a hitherto unknown route to this class of compounds. References [1] T. Beweries, R. Kuzora, U. Rosenthal, A. Schulz, A. Villinger, Angew. Chem. Int. Ed. 2011, 50, 8974–8978. [2] A. Hinz, R. Kuzora, A. Rölke, A. Schulz, A. Villinger, R. Wustrack, Eur. J. Inorg. Chem. 2016, 22, 3611–3619. [3] T. Agou, Y. Sugiyama, T. Sasamori, H. Sakai, Y. Furukawa, N. Takagi, J. Guo, S. Nagase, D. Hashizume, N. Tokitoh, J. Am. Chem. Soc. 2012, 134, 4120−4123.

Uppsala University, SWEDEN O2 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

New synthetic approaches to novel acyclic- and cyclo-polyphosphanes

Robin Schoemaker, Felix Hennersdorf, David Harting, Jan J. Weigand

Chair of Inorganic Molecular Chemistry, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Germany. [email protected]

The use of pyrazole-substituted phosphanes as P1-sources for the synthesis of neutral and cationic polyphosphorus frameworks represents an integral research field of our group.[1] The solvent dependent reaction of dipyrazolylphosphane 1 with dicyclohexylphosphane leads to the formation of polyphosphanes 2 and 3 (Scheme 1).

Scheme 1: Synthesis of triphosphane 2 and pentaphospholane 3 from dipyrazolylphosphane 1. Thus, reacting 1 with dicyclohexylphosphane in acetonitrile in a 1 : 2 ratio leads to triphosphane 2 via a protolysis reaction, while the 1 : 1 reaction in diethyl ether gives pentaphospholane 3 via a P-N/P-P bond metathesis reaction.[1a] Triphosphane 2 reacts with an excess of methyl triflate quantitatively to triphosphane-1,3-diium salt 4[OTf]2 (Scheme 2).

Scheme 2: Methylation of 2 and further reaction to give 5[OTf]2. Pentaphospholane 3 acts as a [Py-P] phosphinidene source to give in a subsequent reaction with [2] 4[OTf]2 the [PyP-PPy] inserted reaction product 5[OTf]2 (Scheme 2). The general and very versatile application of pyrazole-substituted phosphanes for the synthesis of novel polyphosphorus compounds is discussed. Acknowledgement We thank the European Research Council (ERC starting grand, SynPhos - 307616) for financial support. References 1 a) K.-O. Feldmann, J. J. Weigand, J. Am. Chem. Soc. 2012, 134, 15443−15456; b) K.-O. Feldmann, J. J. Weigand, Angew. Chem. Int. Ed. 2012, 51, 7545–7549; c) for a review on oligophosphorus chemistry see M. Donath, F. Hennersdorf, J. J. Weigand, Chem.Soc.Rev. 2016, 45, 1145–1172. 2 for similar diphosphinodiphosphonium dications see a) C. A. Dyker, N. Burford, M. D. Lumsden, A. Decken, J. Am. Chem. Soc. 2006, 128, 9632-9633; b) Y.-Y. Carpenter, C. A. Dyker, N. Burford, M. D. Lumsden, A. Decken, J. Am. Chem. Soc. 2008, 130, 15732-15741.

Uppsala University, SWEDEN O3 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Complexes with low-valent phosphorus ligands Reactions of chalcogenes with phosphanylphosphinidene transition metal complexes

Anna Ordyszewska,a Rafał Grubba,a Łukasz Ponikiewskia and Jerzy Pikiesa

a Department of Inorganic Chemistry, Faculty of Chemistry, Gdansk University of Technology, 11/12 Gabriela Narutowicza Street, 80-233 Gdansk, Poland e-mail: [email protected]

Reactions of transition metal complexes with chalcogenes (O, S, Se) were systematically investigated [1] notwithstanding the reactions of chalcogenes or chalcogene sources with complexes with low-valent phosphorus ligands are rare. For instance, Cummins reported on addition of S-atom into the triple bonded P-atom in [2] [P≡Mo{NAr(R)}3] yielding [S=P=Mo{NAr(R)}3] . Dimeric phosphinidene complex [{Pt(dppe)(μ- [3] PMes)}2] reacts with sulphur to give monomeric [Pt(dppe)(S3PMes)] . Sulphur also reacts with dinuclear manganese complex [Mn2(CO)8{μ-P(TMP)}] yielding dinucler complex bridged with (TMP)P=S ligand [4]. Ruiz et al. studied the reactivity of dinuclear molybdenum phosphinidene [5] complex with S8 . Herein, we made the first attempt to investigate the reactivity of phosphanylphosphinidene transition metal complexes towards chalcogenes and chalcogene sources. As an example anionic phosphanylphosphinidene tungsten complex reacts with elementary selenium yielding new dimeric complex, where P-P bond cleavage occurs and phosphinidene P atom is surrounded by four selenium atoms.

Se

Acknowledgement The authors gratefully acknowledge the National Science Centre, Poland (NCN) for financial support (Project No. 2017/25/N/ST5/00766). References 1 S. Heinl, M. Scheer, Dalton Trans. 2014, 43, 2172-2179. 2 C. C. Cummins, Chem. Commun. 1998, 1777-1786. 3 J. V. Kourkine, D. S. Glueck, Inorg. Chem. 1997, 36, 5160-5164. 4 T.W. Graham, K. A. Udachin, A. J. Carty, Inorg. Chim. Acta., 2007, 360, 1376-1379. 5 M. Alonso, M. A. Alvarez, M. E. García, D. García-Vivó, M. A. Ruiz, Dalton Trans., 2014, 43, 16074- 16083.

Uppsala University, SWEDEN O4 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Intramolecular SEAr reaction of Phosphorous Compounds: mechanistic approaches

Olatz Larrañaga,a Carlos Romero-Nieto,b*Abel de Cózar.*a,c

aDepartamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Universidad del País Vasco and Donostia International Physics Center, P. K. 1072, 20018 San Sebastián - Donostia, Spain. b Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany c IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain. abel.decozar@ ehu.eus

Polyaromatic materials play a fundamental role in organic electronic applications such as field-effect transistors, light-emitting devices, solar cells and sensors.1 In this line, increasing research interest has been devoted to the integration of phosphorus rings into polyaromatic materials. Moreover, the most investigated phosphorus systems for materials applications are based on phospholes2 and phosphabenzenes (phosphininies) have been less studied despite their appealing properties on material sciences. In this communication we will present our results on the mechanism of the formation and optical properties of new phosphorous containing polyaromatic compounds3 (Scheme 1) by means of DFT framework.

Scheme 1 Acknowledgement The authors gratefully acknowledge the Spanish Ministry of Economy and Competitiveness (MINECO CTQ2013-45415P and CTQ2016-80375P). References 1 a) M. Bendikov, F. Wudl, D. F. Perepichka, Chem. Rev. 2004, 104, 4891-4946. b) A. Narita, X.-Y. Wang, X. Feng, K. Müllen, Chem. Soc. Rev. 2015, 44, 6616-6643. c) T. Zhang, D. Liu, Q. Wang, R. Wang, H. Renb, J. Li, J. Mater. Chem., 2011, 21, 12969-12976. d) C. B. Nielsen, S. Holliday, H.-Y. Chen, S. J. Cryer, I. McCulloch, Acc. Chem. Res. 2015, 48, 2803-2812. e) H. Dong, H. Zhu, Q. Meng, X. Gong, W. Hu, Chem. Soc. Rev. 2012, 41, 1754-1808. 2 M. P. Duffy, W. Delaunay, P.-A. Boui, M. Hissler, Chem. Soc. Rev., 2016, 45, 5296-5310. 3 a) C. Romero-Nieto, A. López-Andarias, C. Egler-Lucas, F. Gebert, J. P. Neus, O. Pilgram, Angew. Chem. Int. Ed., 2015, 54, 15872-15875. b) P. Hindenberg, A. López-Andarias, F. Rominger, A. de Cózar, C. Romero-Nieto, Chem. Eur. J. 2017, 23, 13919-13928. c) O. Larrañaga, C. Romero-Nieto, A. de Cózar, Chem. Eur. J. 2017, 23, 17487-17496.

Uppsala University, SWEDEN O5 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Green synthetic routes towards α-hydroxyphosphonates and derivatives

Zita Rádai*, Nóra Zsuzsa Kiss, Viktória Hodula, Réka Szabó, Zoltán Mucsi and György Keglevich

Department of Organic Chemistry and Technology, Budapest University of Technology and Economics. Budapest. Hungary. [email protected]

α-Hydroxyphosphonates have attracted great interest as bioactive organophosphorus species. A green method has been developed for the synthesis of α-hydroxyphosphonates by the addition of dialkyl phosphites to substituted benzaldehydes, in the presence of triethylamine as the catalyst, minimizing the use of volatile organic solvents [1]. The novelty of our method is the “one-pot” synthesis and crystallization step, eliminating the need for additional purification.

The reactions of α-hydroxyphosphonates may lead to valuable compounds. Their substitution with primary amines afforded the corresponding α-aminophosphonates (A) [2], while the catalytic hydrogenation of dibenzyl α-hydroxyphosphonates provided α-hydroxyphosphonic acids (B). The phosphorylation of the α hydroxy group with phosphinic chlorides led to a new family of α- hydroxyphosphonate derivatives (C). The rearrangement of α-hydroxyphosphonates to benzyl phosphates was investigated in the presence of bases (D).

Acknowledgements Z. Rádai is grateful for the fellowship provided by Chinoin–Sanofi Pharmaceuticals and Pro Progressio Foundation. N. Z. Kiss was supported by the New National Excellence Program of the Ministry of Human Capacities (ÚNKP-17-4-I-BME- 133). References 1 G. Keglevich, Z. Rádai, N. Z. Kiss, Green Process. Synth. 2017, 6, 197-201. 2 N. Z. Kiss, Z. Rádai, Z. Mucsi, G. Keglevich, Heteroat. Chem. 2016, 27, 260-268.

Uppsala University, SWEDEN O6 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Triazaphospholenium Tetrafluoroborate: A Phosphorus-Analogue of a 1,2,3-Triazole-Derived Carbene

Martin Papke ,a Lea Dettling,a Julian A. W. Sklorz, a Dénes Szieberth, b László Nyulászi b and Christian Müller a,*

aDepartment of Chemistry and Biochemistry, Freie Universität Berlin. Berlin. Germany; bDepartment of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics and MTA-BME. Budapest. Hungary. @ [email protected]

Since the pioneering work of Bertrand and Arduengo III, heteroatom-stabilized carbenes have emerged to an important and versatile class of compounds during the last decades. 1 Based on the highly flexible copper-catalyzed [3+2] cycloaddition reaction of acetylenes and organoazides, 1,2,3-triazolylidenes of type A have recently been developed as a new class of abnormal carbenes.2 These compounds play a significant role in carbene-chemistry, due to their modular synthesis and flexibility of metal insertion.

Inspired by the obvious analogy between 1,2,3-triazolylidenes and 1,2,3,4-triazaphospholenium salts of type B, we now started to investigate the synthesis, coordination chemistry and possible applications of such a phosphorus compound. 3 According to the principle of valence isoelectronicity, the corresponding phosphorus heterocycle represents the first formal phosphorus analogue of mesoionic carbenes (A).

In general 3H-1,2,3,4-triazaphosphole derivatives can be selectively alkylated with Meerwein´s reagent at the most nucleophilic nitrogen atom. Theoretical calculations revealed that the cation in triazaphospholenium tetrafluoroborate is an aromatic system with a high degree of π-conjugation. First investigations 2- showed that the cationic phosphorus heterocycle can stabilize a [Cu 2Br 4] dianion by formation of a neutral coordination compound with an unusual bonding situation between phosphorus and copper(I).

Acknowledgement Financial support by the Freie Universität Berlin and the DFG Research Training Network 1582 “Fluorine as a Key Element” is gratefully acknowledged.

References 1 a) A. Igau, H. Grützmacher, A. Baceiredo, G. Bertrand, J. Am. Chem. Soc. 1988 , 110 , 6463-6466; b) A. J. Arduengo, R. L. Harlow, M. Kline, J. Am. Chem . Soc . 1991 , 113 , 361-363. 2 P. Mathew, A. Neels, M. Albrecht, J. Am. Chem. Soc . 2008 , 130 , 13534-13535. 3 M. Papke, L. Dettling, J. A. W. Sklorz, D. Szieberth, L. Nyulászi, C. Müller, Angew. Chem. Int. Ed . 2017 , 56 , 16484-16489.

Uppsala University, SWEDEN O7 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Expanding the Pool of Phosphorus Rich Ferrocenophanes

Denis Kargin,a Stefan Isenberg,a Zsolt Kelemena and Rudolf Pietschniga,*

aUniversity of Kassel, Institute of Chemistry, Chemical Hybrid Materials, Kassel, Germany. [email protected]

[n]Ferrocenophanes (especially n=1) are attractive monomers for the ring opening polymerization (ROP) to ferrocenylene based phosphorus polymers.[1] The ring strain present in these type of molecules render them thermally unstable. Although, the tendency for thermal ROP is significantly reduced for n=2,3 the number of phosphorus containing ferrocenophanes with two or more phosphorus atoms in the bridge is rather small.[2-4] Due to their stereogenic properties the number of diastereomers increases with the number of phosphorus atoms in a chain, which can be reduced by embedding the chain into a cyclic ferrocenophane backbone.[3,4] We present a bundle of new phospha [n]ferrocenophanes incorporating different main group elements, various synthetic approaches and addressing different attributes including stereo-, tetrylene- and electrochemistry as well as radical generation and polymerization.

trans cis

Acknowledgement The authors gratefully acknowledge financial support by the DFG (PI 353/8-1 & 9-1), SFB 1319 (ELCH) and COST action CN 1302 (SIPs).

References [1] Pietschnig, Chem. Soc. Rev. 2016, 45, 5216; Manners, Angew. Chem. Int. Ed. 2007, 46, 5060. [2] Mizuta et al., J. Organomet. Chem. 2012, 713, 80; Dalton Trans. 2016, 45, 19034. [3] Pietschnig et al., Chem. Eur. J. 2017, 23, 10438; Dalton Trans. 2016, 45, 2180. [4] Pietschnig et al., Chem. Eur. J. 2009, 46, 12589.

Uppsala University, SWEDEN O8 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Lubricant Chemistry at the Interface of Surfaces Organophosphorus Additive Interactions in Engine Lubricant Formulations

M. Heeran,a J. C. Speelmanb and P. W. Dyera,*

a Department of Chemistry, Durham University, Durham, UK. b AkzoNobel Surface Chemistry, Deventer, NL. [email protected]

Friction modifiers R Anti-foam Anti- agents oxidants RO S OR N ZDDPs S R P Zn P S Viscosity RO S OR Dispersants improver ZDDP Friction Modifier Detergents

Zinc dialkyl/diaryl dithiophosphates (ZDDPs), Zn{S2P(OR)2}, are the most successful lubricant additives ever developed. They offer not only antioxidant, but also long-lasting anti-wear and extreme pressure properties. However, in modern crankcase engine lubricants, ZDDPs are used alongside a myriad of other additives, thereby creating the potential for both synergistic and/or antagonistic interactions in solution.1 The scientific understanding and consequences of any such interactions however, is an area that is significantly under-developed, and thus hinders the development of next- generation engine lubricant systems. The convergence of emission and fuel economy demands alongside tighter legislation,2 in particular, highlights the pressing need for a fundamental understanding of additive-additive interactions to enable the design and development of new lubricant package formulations, which meet the contradictory future demands of engine lubricants. Here, we expose the complex nature and impact of solution-phase interactions of ZDDPs with various amine-functional friction modifiers of commercial interest, or suitable model amine alternatives where applicable. For example, complexation can occur, which takes place through amine coordination to the zinc centre of ZDDP and is accompanied by a significant change in coordination behaviour of the associated dithiophosphate ligands, that in turn affects the degradation of the ZDDP moiety – a key feature in providing essential anti-wear properties. Acknowledgement The authors gratefully acknowledge AkzoNobel and the EPSRC CDT in Soft Matter and Functional Interfaces (Grant Ref. No. EP/L015536/1) for funding. References 1 H. Spikes, Tribol. Lett., 2004, 17, 469-489. 2 V. W. Wong and S. C. Tung, Friction, 2016, 4, 1-28.

Uppsala University, SWEDEN O9 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Dispersion forces in Frustrated Lewis pair chemistry Flip Holtrop and J. Chris Slootweg*

Main group chemistry & catalysis, Van ‘t Hoff Institute for Molecular Sciences, University of Amsterdam, Netherlands [email protected]

Frustrated Lewis pairs (FLPs) combine a Lewis acidic and Lewis basic site to activate small molecules granting access to interesting main group chemistry and catalysis. For example, FLPs are able to heterolytically cleave dihydrogen allowing for their use as organocatalysts in hydrogenation reactions.1 In addition, FLPs can activate a variety of small molecules illustrating their potential for further organocatalytic applications. This unique reactivity is the result of synergistic interaction of a Lewis acid and base with the substrate. To achieve this, the Lewis acid and base are proposed to preform a van der Waals complex creating a reactive pocket in which a small molecule can subsequently be activated.2 This highlights the importance of dispersion forces in frustrated Lewis pair chemistry.

This work explores both the van der Waals forces in Lewis adduct and frustrated Lewis pair formation, and the synthesis of FLP van der Waals complexes to elucidate the mechanism of small molecule activation within their reactive pockets.

References 1 a D. Stephan, G. Erker, Angew. Chem. Int. Ed. 2015, 54, 6400 b D. Stephan, Science 2016, 354, 1248 2 a G. Skara, F. De Vleeschouwer, P. Geerlings, F. De Proft, B. Pinter, Scientific Reports 2017, 7, 16024 b L. Rocchigiani, G. Ciancaleoni, C. Zuccaccia, A. Macchioni, J. Am. Chem. Soc. 2014, 136, 112

Uppsala University, SWEDEN O10 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Pt(0)-catalysed Hydrophosphination as a Route to Diphosphine Ligands for SPECT Imaging

Ailis Chadwick,a, b Martin Heckenast,a Paul G. Pringle*,a James Race,a Michelle T. Ma,b Philip J. Blower.b a School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, UK b King's College London, Division of Imaging Sciences and Biomedical Engineering, St Thomas' Hospital, London SE1 7EH, UK [email protected]

Hydrophosphination, the addition of a P‒H bond across a multiple bond, may be achieved by a variety of routes including acid- or base-catalysis, and radical initiation.1 Of the large number of methods available, transition metal-catalysis provides the greatest potential to combine high atom‒efficiency with selectivity to create new phosphorus‒carbon bonds.2

Platinum(0)‒catalysed hydrophosphination of activated alkenes offers access to functionalized phosphines that have proved useful as ligands for homogeneous catalysis.3 This process was first reported in 1990 when it was shown that addition of PH3 to acrylonitrile was catalysed by a platinum(0) complex.4

Investigations into the mechanism of platinum(0)‒catalysed hydrophosphination have focused on the synthesis of monophosphines.5 Surprisingly, despite the possibility of catalyst poisoning by substrate chelation, functionalized diphosphines can also be prepared via this method.6 Here we demonstrate the efficient and selective hydrophosphination of unsymmetrical diphosphine 1 to give 2 and related diphos ligands and investigate the mechanism of these transformations.

The coordination chemistry of 2 with Pt(II), Tc(V) and Re(V) has been explored for application to SPECT imaging and radiotherapy.

References (1) Costa, E.; Pringle, P. G.; Smith, M. B.; Worboys, K. J. Chem. Soc., Dalton Trans. 1997, 4277. (2) Espinal-Viguri, M.; King, A. K.; Lowe, J. P.; Mahon, M. H.; Webster, R. L. ACS Catal. 2016, 6, 7892. (3) Wicht, D. K.; Kourkine, I. V.; Lew, B. M.; Nthenge, J. M.; Glueck, D. S. J. Am. Chem. Soc. 1997, 119, 5039. (4) Pringle, P. G.; Smith, M. B. J. Chem. Soc. Chem. Commun. 1990, 1701. (5) Scriban, C.; Kovacik, I.; Glueck, D. S. Organometallics 2005, 24, 4871. (6) Kovacik, I.; Scriban, C.; Glueck, D. S. Organometallics 2006, 25, 536.

Uppsala University, SWEDEN O11 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

A P-H Functionalized Al/P Based Frustrated Lewis Pair - Substrate Activation and Hydrophosphination

Lukas Keweloha, Werner Uhla

aInstitut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität, Münster, Germany. [email protected]

Hydroalumination of the secondary alkynylphosphine 1 with the bulky hydride Bis2Al-H affords the P-H functionalized FLP 21. The P-H group represents a new approach in FLP chemistry with an additional active moiety. 2 shows the dipolar substrate complexation similar to conventional FLPs followed by hydrophosphination of various activated substrates2,3.

Many functional groups with unsaturated CN bonds such as nitriles (3), azides (4), cyanates, isocyanates and carbodiimides have been reduced by H shift to N. Diphenyl-cyclopropenon (5) undergoes a ring opening reaction with P-H addition of the strained CC single bond. A kinetically hindered hydrogen migration, observed at a keteneimine (6), is facilitated by DABCO as proton transfer reactant, here by C-H bond formation (7). The products are formed in highly selective reactions.

References

1 L. Keweloh, H. Klöcker, E.-U. Würthwein, W. Uhl, Angew. Chem. 2016, 55, 3212. 2 W. Uhl, L. Keweloh, A. Hepp, F. Stegemann, M. Layh, K. Bergander, Z. Anorg. Allg. Chem. 2017, 643, 1978. 3 W. Uhl, J. Backs, A. Hepp, L. Keweloh, M. Layh, D. Pleschka, J. Possart, Z. Naturforsch. 2017, 72b, 821.

Uppsala University, SWEDEN O12 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

A simple route to phosphinecarboxamides: reactivity of the PCO ̅ anion towards amino acids and hydrazine

Erica N. Faria,a Andrew R. Jupp,a Jose M. Goicoecheaa,*

aDepartment of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, OX1 3TA. Oxford. United Kingdom. [email protected]

The 2-phosphaethynolate anion (PCO–, a heavier analogue of cyanate), was first reported in 1992 as a lithium salt by Becker and co-workers.1 However, given the inherent reactivity of this salt, this novel anion was not extensively studied. Recently, the synthesis of more stable salts has been reported by using heavier alkali metal counter cations.2–5

In 1828, Wöhler reported the synthesis of urea by the reaction between silver cyanate and ammonium chloride. Inspired by this seminal study, we explored the reactivity of PCO– towards ammonium salts. This research resulted in the synthesis of phosphinecarboxamide (PH2C(O)NH2), a heavier analogue of urea, which is both air and moisture stable, unlike most primary phosphines.6, 7

Reactions between PCO– and amino acids afforded sodium salts of functionalized amino acids which can readly be protonated (see figure). Reactions involving hydrazine hydrochlorides can similarly be used to afford novel neutral phosphines.

Acknowledgement The authors gratefully acknowledge the Conselho Nacional Desenvolvimento Científico e Tecnológico (CNPq) and the EPRSC for financial support. References 1 G. Becker, W. Schwarz, N. Seidler, M. Westerhausen. Z. Anorg. Allg. Chem. 1992, 612 (6), 72–82. 2 F. F. Puschmann, D. Stein, D. Heift,C. Hendriksen, Z. A. Gal, H.F. Grützmacher, H. Grützmacher. Angew. Chem. Int.Ed. 2011, 50 (36), 8420–8423. 3 A. R. Jupp, J. M. Goicoechea. Angew. Chem. Int. Ed. 2013, 52 (38), 10064–10067. 4 D. Heift, Z. Benko, H. Grutzmacher. Dalton Trans. 2014, 43 (2), 831–840. 5 Z. J. Quan, X. C. Wang. Org. Chem. Front. 2014, 1 (9), 1128–1131. 6 A. R. Jupp, J. M. Goicoechea. J. Am. Chem. Soc. 2013, 135 (51), 19131–19134. 7 C. A. Tsipis, P. A. Karipidis. J. Am. Chem. Soc. 2003, 125 (8), 2307–2318.

Uppsala University, SWEDEN O13 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis and reactions of novel 1,4-diphosphinines

Imtiaz Begum,a Z. Kelemen b, L. Nyulászi b* and R. Streubel c,*

aUniversity of Bonn, Institute of Inorganic Chemistry, Gerhard-Domagk-Str.1, 53121 Bonn, Germany. bBudapest University of Technology and Economics [email protected]

Phosphinines such as I represent a landmark discovery in phosphorus chemistry[1] which has stimu- lated intensive studies on synthesis and ligand properties. But it also spurred a rapid development in heterocyclic and low-coordinate phosphorus chemistry. However, only the monocyclic example of a 1,4-diphosphinine II[2] was reported for a long time, but in 2017 we described a route to III.[3]

Scheme 1. Previously reported phosphinine I and 1,4-diphosphinines II,III.

Herein, synthesis of thiazole-2-thione-based tricyclic 1,4-diphosphinine 2 using 1 as precursor is des- cribed. Reactivity studies reveal a rich and versatile chemistry of 2 including such reactions with nucleophiles and electrophiles to give 3 as well as concerted reactions to provide 1,4-diphospha- barellene 4.[4] This and more will be presented during this lecture.

Scheme 2. Synthesis of 1,4-diphosphinine 2 and its reactions with a nucleophile electrophile pair to give 3 and concerted reactions to provide 1,4-diphosphabarellene 4.

Acknowledgement I. Begum is greatful to DAAD for a PhD fellowship and the COST action CM1302 (SIPs) for financial support. References 1 Märkl, Angew. Chem. Int. Ed. Engl, 1966, 5, 846. 2 Y. Kobayashi, J. Kumadaki, A. Ohsawa, W. Hamana, Tetrahedron Lett, 1976, 3715. 3 A. Koner, G. Pfeifer, Z. Kelemen, G. Schnakenburg, L. Nyulászi, T. Sasamori, R. Streubel, Angew. Chem. Int. Ed, 2017, 56, 9231. 4 I. Begum, Z. Kelemen, G. Schnakenburg, L. Nyulászi, R. Streubel, submitted, 2018.

Uppsala University, SWEDEN O14 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Nucleophilic Activation of Sulfur Hexafluoride: Metal-free, Selective Degradation by Phosphines

Florenz Buß, Christian Mück-Lichtenfeld, Paul Mehlmann and Fabian Dielmann*

Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster. Germany. @ [email protected]

The development of new methods for the chemical activation of inert greenhouse gases such as sulfur hexafluoride (SF6), carbon dioxide (CO2) and nitrous oxide (N2O) not only is of current environmental interest, but also offers new opportunities for their efficient use as feedstock in organic synthesis. Regarding SF6, examples for the mild chemical activation are rare and metal-free procedures for the complete degradation of SF6 have not yet been identified. Our strategy to activate SF6 under mild conditions is based on the use of electron-rich phosphines with imidazolin-2- ylidenamino substitutents (IAPs). These phosphines are more basic than alkyl- and aryl- phosphines.[1] NMR studies, X-ray crystallographic studies, DFT calculations as well as a scalable [2] one-pot procedure for the complete degradation of SF6 are depicted in detail on the poster.

Nucleophilic activation and degradation of SF6 by electron-rich phosphines.

Acknowledgement The authors gratefully acknowledge financial support from the DFG (IRTG 2027, SFB 858). References 1 a) F. Buß, P. Mehlmann, C. Mück-Lichtenfeld, K. Bergander, J. Am. Chem. Soc. 2016, 138, 1840. b) P. Mehlmann, C. Mück-Lichtenfeld, T. Tan, F. Dielmann, Chem. Eur. J. 2017, 23, 5929. 2 a) F. Buß, C. Mück-Lichtenfeld, P. Mehlmann, F. Dielmann Angew. Chem. Int. Ed. 2018, DOI: 10.1002/anie.201713206R2. b) F. Buß and F. Dielmann; German patent application DE 10 2017 124 415.8

Uppsala University, SWEDEN O15 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Self-assembled Networks of Nano-Sized Spherical Supramolecules 5 Coordination Chemistry of [Cp*Fe(η -P5)], AgSbF6 and flexible Dinitriles

Barbara Krämer, Manfred Scheer

Institute of Inorganic Chemistry, University of Regensburg. Regensburg. Germany. [email protected]

5 Over the years the Pn ligand complex [Cp*Fe(η -P5)] has been established as a versatile building block in coordination chemistry driven by self-assembly processes. With coinage metal salts 1D and 2D[1] polymeric compounds could be characterized, as well as nano-sized spherical supramolecules[2] are accessible via a template-controlled assembly.

By applying appropriate conditions and adding fully flexible dinitrile linker molecules NC(CH2)xCN 5 (x = 5-10) to the building blocks [Cp*Fe(η -P5)] and AgSbF6, polymeric networks are formed. While the shorter linker molecules (x = 5, 6) lead to 1D, 2D and 3D three-component polymeric structures, the longer linker with x ≥ 7 open the door to a unprecedented class of compounds (Scheme 1). Thus, several entirely self-assembled 3D networks of connected spherical supramolecules could be characterized as its first representatives. Moreover, the nano-sized spheres exhibit inner voids to host smaller molecules.

5 Scheme 1: Detail of a fcc type 3D network of connected spheres consisting of [Cp*Fe( -P5)], AgSbF6 and a flexible dinitrile. [Cp*Fe] units, anions and encapsulated molecules are not depicted.

Acknowledgement The authors gratefully thank the European Research Council (ERC) for the SELFPHOS AdG-339072 project. References 1 a) M. Scheer, L. J. Gregoriades, A. V. Virovets, W. Kunz, R. Neueder, I. Krossing, Angew. Chem. Int. Ed. 2006, 45, 5689-5693; b) F. Dielmann, A. Schindler, S. Scheuermayer, J. Bai, R. Merkle, M. Zabel, A. V. Virovets, E. V. Peresypkina, G. Brunklaus, H. Eckert, M. Scheer, Chem. Eur. J. 2012, 18, 1168-1179. 2 a) J. Bai, A. V. Virovets, M. Scheer, Science 2003, 300, 781-783; b) M. Scheer, A. Schindler, R. Merkle, B. P. Johnson, M. Linseis, R. Winter, C. E. Anson, A. V. Virovets, J. Am. Chem. Soc. 2007, 129, 13386- 13387; c) A. Schindler, C. Heindl, G. Balazs, C. Groeger, A. V. Virovets, E. V. Peresypkina, M. Scheer, Chem. Eur. J. 2012, 18, 829-835; d) C. Schwarzmaier, A. Schindler, C. Heindl, S. Scheuermayer, E. V. Peresypkina, A. V. Virovets, M. Neumeier, R. Gschwind, M. Scheer, Angew. Chem. Int. Ed. 2013, 52, 10896-10899.

Uppsala University, SWEDEN O16 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

2D black phosphorus decorated with palladium nanoparticles. Synthesis, characterization and catalytic applications

Matteo Vanni,a Manuel Serrano-Ruiz,a Francesca Telesio,b Stefan Heun,b Maria Caporali,a Maurizio Peruzzinia a CNR ICCOM, Istituto di Chimica dei Composti Organometallici, Via Madonna del Piano, 10, 50019 Sesto Fiorentino (Italy). b NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro, 12, 56121 Pisa (Italy). [email protected]

Black phosphorus, firstly prepared by physicist Percy Bridgman in 1914, was recently rediscovered after the report of its mechanical exfoliation.(1) The resulting bidimensional material (2D BP), a phosphorus-based counterpart of graphene, aroused tremendous interest given its semiconductor properties with a layer dependent band gap, ranging from 0.3 eV (bulk material) to 2.0 eV (monolayer). However, a major drawback limiting the applications of 2D BP is its instability toward the mutual effect of oxygen, water and light. In our labs, 2D BP was prepared by sonochemically assisted solvent exfoliation of bulk black phosphorus under inert atmosphere.(2) We speculated that given the formal presence of a lone pair on each P-atom, 2D BP would be an excellent material to anchor metal nanoparticles(3) and turned our attention on palladium. The growth of palladium nanoparticles was performed in situ by reduction of a Pd(II) salt previously impregnated on the surface of 2D BP. TEM observation of the resulting material (Pd@BP) showed a good covering of 2D BP flakes by Pd nanoparticles. Pd@BP was then tested as catalyst in the hydrogenation of halonitroarenes to haloanilines, a reaction often affected by dehalogenation byproducts. Higher selectivity compared to known heterogeneous catalysts based on supported Pd nanoparticles was observed, pointing out the relevant role of 2D BP as support.

Acknowledgement This work was supported by an ERC Advanced Grant PHOSFUN "Phosphorene functionalization: a new platform for advanced multifunctional materials” (Grant Agreement No. 670173) to M. P.

References 1 L. Li, Y. Yu, G. J. Ye, Q. Je, X. Ou, H. Wu, D. Feng, X. H. Chen, Y. Zhang, Nat. Nanotech. 2014, 9, 372. 2 M. Serrano-Ruiz, M. Caporali, A. Ienco, V. Piazza, S. Heun, M. Peruzzini, Adv. Mater. Interfaces 2016, 3, 1500441. 3 M. Caporali, M. Serrano-Ruiz, F. Telesio, S. Heun, G. Nicotra, C. Spinella, M. Peruzzini, Chem. Commun., 2017, 53, 10946-10949.

Uppsala University, SWEDEN O17 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis and Reactivity of 2 2 2 Nickel-Stabilised µ :η ,η -P2, As2 and PAs Units

Gabriele Hierlmeier,a Alexander Hinz,b Robert Wolfa,* and Jose Manuel Goicoecheab,*

aUniversity of Regensburg, Institute of Inorganic Chemistry, 93040 Regensburg, Germany. b Department of Chemistry, University of Oxford, Department of Chemistry, 12 Mansfield Road, OX1 3TA Oxford (UK), United Kingdom. [email protected]

Despite still being regarded as rare, the chemistry of nickel compounds in the +1 oxidation state has undergone significant development over the last decades.[1] At the same time, the reactivity of the heavier group 15 cyanate analogue 2-phosphaethynolate PCO− has also rapidly evolved due to the stability and facile preparation of its sodium salt NaPCO.[2] This small anion has been shown to undergo salt metathesis reactions with metal halides which led to a variety of unprecedented phosphorus-containing compounds.[3] Nickel(I) complexes of the type [CpNi(NHC)] (NHC = IMes, IPr)[4] react in salt metathesis reactions with the heavier group 15 cyanate analogues NaPCO and NaAsCO, giving rise to [NiPn(CO)(NHC)]2 2:2 complexes (Pn = P, As) with μ,η -Pn2 units. Intermediates in these reactions such as phosphinidyne complexes and phosphaketenes were isolated and characterised. Moreover, the new [NiPn(CO)(IMes)]2 complexes release white phosphorus (P4) and elemental arsenic via Pn2 type intermediates upon reaction with CO.[5]

References 1 C.-Y. Lin, P. P. Power, Chem. Soc. Rev. 2017, 46, 5397. 2 a) F. F. Puschmann, D. Stein, D. Heift, C. Hendriksen, Z. A. Gal, H.-F. Grützmacher, H. Grützmacher, Angew. Chem. Int. Ed. 2011, 50, 8420; b) D. Heift, Z. Benko, H. Grützmacher, Dalton trans. 2014, 43, 831; c) A. Hinz, J. M. Goicoechea, Angew. Chem. Int. Ed. 2016, 55, 8536. 3 a) L. Liu, D. A. Ruiz, F. Dahcheh, G. Bertrand, R. Suter, A. M. Tondreau, H. Grützmacher, Chem. Sci. 2016, 7, 2335; b) L. N. Grant, B. Pinter, B. C. Manor, R. Suter, H. Grützmacher, D. J. Mindiola, Chem. Eur. J. 2017, 23, 6272; c) C. Camp, N. Settineri, J. Lefèvre, A. R. Jupp, J. M. Goicoechea, L. Maron, J. Arnold, Chem. Sci. 2015, 6, 6379. 4 a) S. Pelties, D. Herrmann, B. de Bruin, F. Hartl, R. Wolf, Chem. Commun. 2014, 50, 7014; b) S. Pelties, R. Wolf, Organometallics 2016, 35, 2722; c) S. Pelties, A. W. Ehlers, R. Wolf, Chem. Commun. 2016, 52, 6601. 5 G. Hierlmeier, A. Hinz, R. Wolf, J. M. Goicoechea, Angew. Chem. Int. Ed. 2018, 57, 431; Angew. Chem. 2018, 130, 439.

Uppsala University, SWEDEN O18 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis of contorted Polycyclic Aromatic Hydrocarbons by cycloadditions from polycyclic phospholes

a, a b b Réka Mokrai,a, b Rózsa Szűcs, b Pierre-Antoine Bouit, László Nyulászi, Zoltán Benkő, and Muriel Hisslera,* a Univ Rennes, CNRS, ISCR – UMR 6226, F-35000 Rennes, France; b Inorganic and Analytical Chemisrty Department, Budapest University of Technology and Economics. Budapest. Hungary. @ [email protected]

Polycyclic Aromatic Hydrocarbons (PAHs) are important experimental and theoretical objects due to their unique electronic properties making them appealing for applications in molecular electronics such as organic solar cells and field effect transistors.a-c Their physical properties can be modified by embedding heteroatoms into the sp2 backbone. For example, we synthesized P-containing PAHs and demonstrated that the chemical modifications performed at the P-atom such as complexation or oxidation, had a significant influence on the optical properties of the molecules.d-f During the aromaticity studies of P-containing PAHs, we have established that modification of the local aromaticity of the five-membered ring (by chemical modifications of the phosphorus atom) has a significant impact on the local aromaticities of the other rings. It has been shown both experimentally and theoretically that the Diels-Alder cycloadditiong of the P-embedded PAHs proceeds at the heterocyclic rings that exhibit the lowest aromaticity in the π-system. Then, these reactions were used to synthesize non-planar all- carbon PAHs. The mechanism of this novel approach to PAHs has been studied experimentally and computationally (DFT calculations). The new PAHs are characterized by NMR spectroscopy and single crystal X-ray diffraction. The optical and electrochemical properties have been studied and complemented by DFT calculations. In conclusion, the physical properties of these compounds make them valuable building blocks for the development of active molecules in devices.

Acknowledgement The authors gratefully acknowledge the Campus France, Tempus Public Foundation, Pro Progressio Alapítvány, Hungarian-French TéT Program TÉT_16-1- 2016-0128. References a) M. D. Watson, A. Fechtenkötter, K. Müllen, Chem. Rev. 2001, 101, 1267-1300. b) W. Pisula, X. Feng, K. Müllen, Chem. Matter. 2011, 23, 554-567. c) J. Wu, W. Pisula, K. Müllen, Chem. Rev. 2007, 107, 718-747. d) P-A. Bouit, A. Escande, R. Szűcs, D. Szieberth, C. Lescop, L. Nyulászi, M. Hissler, R. Réau J. Am. Chem. Soc. 2012, 134, 6524-6527. e) R. Szűcs, P-A. Bouit, L. Nyulászi, M. Hissler ChemPhysChem. 2017, 18, 2618-2630. f) F. Riobé, R. Szűcs, C. Lescop, R. Réau, L. Nyulászi, P-A. Bouit, M. Hissler Organometallics 2017, 36, 2502- 25011.

g) F. Mathey, F. Mercier, C. Charrier J. Am. Chem. Soc. 1981, 103, 4595-4597.

Uppsala University, SWEDEN O19 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

BN and BP Analogues of Poly(p-phenylene vinylene) (PPV)

Merian Crumbach, Thomas Lorenz, Holger Helten*

Institute of Inorganic Chemistry, RWTH Aachen University, Aachen, Germany [email protected]

Substitution of selected CC units by their isoelectronic and isosteric BN units in π-conjugated organic systems (BN/CC isosterism) has emerged as a viable strategy to produce novel materials with structural similarities to their all-carbon congeners, but in many cases fundamentally altered electronic features.1 While this concept has been successfully applied to mono- and polycyclic aromatic hydrocarbons, first examples have just demonstrated its applicability to polymer chemistry.2-4 The incorporation of BP units, on the other hand, which are valence isoelectronic with BN and CC, into unsaturated organic compounds has been scarcely studied, though the potential of the resulting BCP hybrid materials for electronic applications has been recognized quite recently.5 Main chain-conjugated polymers featuring BP fragments in the backbone are unknown so far. Recently, we have introduced /boron exchange polycondensation as a novel polymerization method.3 Herein, the synthesis and characterization of the first poly(p-phenylene iminoborane) (BN- PPV) is presented.4 This novel inorganic–organic hybrid polymer can be regarded as a BN analogue of the well-known poly(p-phenylene vinylene) (PPV). Photophysical studies, supported by TD-DFT calculations, as well as molecular structures of model oligomers will also be discussed. Furthermore, our recent advances in the preparation of BP analogues of PPV (BP-PPV) will be presented.6

Acknowledgements The authors gratefully acknowledge the COST action CM1302 (SIPs), and the German Research Foundation (DFG) for funding through the Emmy Noether Programme and the Research Grant HE 6171/4-1.

References 1 M. J. D. Bosdet, W. Piers, Can. J. Chem. 2009, 87, 8-29. 2 a) A. W. Baggett, F. Guo, B. Li, S.-Y. Liu, F. Jäkle, Angew. Chem. Int. Ed. 2015, 54, 11191-11195; b) X.-Y. Wang, F.- D. Zhuang, J.-Y. Wang, J. Pei, Chem. Commun. 2015, 51, 17532-17535. 3 a) T. Lorenz, A. Lik, F. A. Plamper, H. Helten, Angew. Chem. Int. Ed. 2016, 55, 7236-7241; b) O. Ayhan, T. Eckert, F. A. Plamper, H. Helten, Angew. Chem. Int. Ed. 2016, 55, 13321-13325; c) H. Helten, Chem. Eur. J. 2016, 22, 12972- 12982; d) A. Lik, L. Fritze, L. Müller, H. Helten, J. Am. Chem. Soc. 2017, 139, 5692-5695; e) N. A. Riensch, A. Deniz, S. Kühl, L. Müller, A. Adams, A. Pich, H. Helten, Polym. Chem. 2017, 8, 5264-5268; f) O. Ayhan, N. A. Riensch, C. Glasmacher, H. Helten, Chem. Eur. J. 2018, 10.1002/chem.201705913. 4 T. Lorenz, M. Crumbach, T. Eckert, A. Lik, H. Helten, Angew. Chem. Int. Ed. 2017, 56, 2780-2784. 5 a) A. Tsurusaki, T. Sasamori, A. Wakamiya, S. Yamaguchi, K. Nagura, S. Irle, N. Tokitoh, Angew. Chem. Int. Ed. 2011, 50, 10940-10943; b) J. H. Barnard, P. A. Brown, K. L. Shuford, C. D. Martin, Angew. Chem. Int. Ed. 2015, 54, 12083– 12086; c) J. A. Bailey, M. F. Haddow, P. G. Pringle, Chem. Commun. 2014, 50, 1432–1434; d) A. N. Price, G. S. Nichol, M. J. Cowley, Angew. Chem. Int. Ed. 2017, 56, 9953–9957. 6 M. Crumbach, T. Lorenz, H. Helten, manuscript in preparation.

Uppsala University, SWEDEN O20 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Oxidative P−P Bond Addition to Cobalt(−I)

P. Coburger,a S. Demeshko,b , C. Rödl,c R. Wolfc and E. Hey-Hawkinsa,* a Leipzig University, Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Johannisallee 29, D-04103 Leipzig. b Georg-August-Universität Göttingen, Faculty of Chemistry, Tammannstraße 4, D-37077 Göttingen. c Regensburg University, Faculty of Chemistry and Pharmacy, Universitätsstraße 31, D-93053 Regensburg @ [email protected]

Homoleptic tetrahedral low-spin complexes of first-row transition metals are rare due to the weak 1 t 2 ligand-field splitting of classic ligands. Examples like [Co(norbornyl)4] or [Mn(N=C Bu2)4] require high oxidation states of the metal (+4) and strong σ-donor ligands, like alkyl groups, or strong π- donating and π-accepting ligands, like ketimides. Here, we present the synthesis and characterisation of a diamagnetic homoleptic cobalt- bis(phosphanido) complex (1) (Figure 1), featuring cobalt in the oxidation state +3.3

Figure 1: Section of the one-dimensional structure of 1 in the solid state with ellipsoids drawn at 50% probability level. Hydrogen atoms (other than the CH and BH groups involved in interactions) have been ommitted for clarity. tert-Butyl groups have been drawn as wireframes for clarity.

Acknowledgement The authors gratefully acknowledge the COST Action CM1302 (SIPs). Financial support by the Studienstiftung des deutschen Volkes (doctoral fellowship to P.C.) and the graduate school BuildMoNa (Leipzig University) is gratefully acknowledged. References 1 E. K. Byrne, D. S. Richeson, K. H. Theopold, J. Chem. Soc., Chem. Commun. 1986, 1491-1492. 2 R. A. Lewis, G. Wu, T. W. Hayton, Inorg. Chem. 2011, 50, 4660-4668. 3 P. Coburger, S. Demeshko, C. Rödl, E. Hey-Hawkins, R. Wolf, Angew. Chem. Int. Ed. 2017, 56, 15871-15875; Angew. Chem. 2017, 129, 16087-16091.

Uppsala University, SWEDEN O21 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Metalated diaminophosphine-boranes: functionalized P-nucleophiles

M. Bluma, T. Dunaja, J. Kapplera, C. Feila, W. Freyb, S. H. Schlindweina and D. Gudata

aInstitut für Anorganische Chemie, bInstitut für Organische Chemie, Universität Stuttgart, Stuttgart, Germany. Email: [email protected]

Formation of phosphorus-element bonds by reaction of a P-nucleophile with a suitable electrophile is of great interest in organoelement chemistry and alkaline metal phosphanides[1] derived from secondary alkyl, aryl or trimethylsilyl phosphines have become important synthetic tools. In contrast, examples of P-nucleophiles with electronegative substituents like amino-groups are confined to a single report by Knochel et al. who postulated that the reductive coupling of a diamino- chlorophosphine-borane with organic electrophiles proceeds via a transient metalated diaminophosphine-borane.[2] Even if no direct evidence for the intermediate was obtained, species of this type could be interesting synthons for molecular chemistry. Herein, we present an alternative pathway for the generation of lithiated diaminophosphine-boranes. Both the initial products and their transmetalation products could be characterized spectroscopically or structurally for the first time.[3] Finally, we also report on metathesis reactions with organoelement electrophiles to afford new multifunctional phosphine-boranes.

Figure 1: Functionalization of a diaminophosphine-borane. M = Li, K; E = SiMe2.

Acknowledgement The authors gratefully thank the bwHPC-C5 project of Baden-Württemberg for providing high performance computing clusters and the University of Stuttgart for financial support. References [1] K. Issleib, A. Tzschach , Chem. Ber., 1959, 92, 1118-1126. [2] A. Longeau, P. Knochel, Tetr. Let., 1996, 37, 6099-6102. [3] M. Blum, J. Kappler, S. H. Schlindwein, M. Nieger, D. Gudat, DaltonTrans. , 2018, 47, 112-119.

Uppsala University, SWEDEN O22 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

An Organocatalytic Approach to P-Stereogenicity

Martin Ó Fearraigha and Eoghan McGarriglea*

aSchool of Chemistry, Universtiy College Dublin. Dublin. Ireland. @ [email protected]

P-stereogenic molecules have found applications as ligands, catalysts and as biologically active molecules.[1] However routes for their asymmetric synthesis are far less numerous than their carbon analogues. To enable their full potential to be realized new methods need to be developed. These should be catalytic asymmetric methods and should start from readily available, cheap phosphorus- containing compounds. They must be efficient in their use of phosphorus – classified as an endangered element.[2]

Chiral organocatalysts containing thiourea/urea feature prominently in asymmetric synthesis and have been explored as excellent alternatives to transition-metal catalysts for their cost and operational simplicity. These catalysts have delivered high selectivities, proposed to proceed via anion abstraction binding or hydrogen bonding modes of action.[3] We aim to exploit this anion abstraction/binding motif of chiral thiourea/urea catalysts to render enantiopure compounds from readily available racemic or prochiral P-containing starting materials.

Acknowledgement The authors gratefully acknowledge the Irish Research Council (GOIPG/2014/528). References 1 a) S. Connon, Angew. Chem. Int. Ed. 2006, 45, 3909-3912. b) W. Tang, X. Zhang, Chem. Rev. 2003, 103, 3029- 3070. c) G. Birkus, R. Wang, X. Liu, N. Kutty, H. MacArthur, T. Cihlar, C. Gibbs, S. Swaminathan, W. Lee, M. McDermott, Antimicrob. Agents Chemother. 2007, 51, 543-550. 2 O. Kolodiazhnyi, In Asymmetric Synthesis in Organophosphorous Chemisrty; Synthetic Methods, Catalysis and Applications, 1st ed.; Wiley-VCH Verlag GmbH & Co. KGaA: Weinheim, Germany, 2017; Chapter 2. 3 a) K. Brak, E. Jacobsen, Angew. Chem. Int. Ed. 2013, 52, 534-561. b) N. Mittal, K. Lippert C. Kanta De, E. Klauber, T. Emge, P. Screiner, D. Seidel, J. Am. Chem.Soc. 2005, 137, 5748-5758.

Uppsala University, SWEDEN O23 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Reductive one-pot coupling of two aldehydes to unsymmetric E-alkenes via phosphaalkene and subsequent phosphinate intermediates

Juri Maia, Sascha Otta.

aUppsala University, Department of Chemistry, Ångström laboratory, 75120 Uppsala, Sweden [email protected]

The structural motif of C=C double bonds in nature and commodity chemicals – such as plastics, pigments, drugs or lipids and vitamins – is omnipresent. Thus, the development of new methodologies for the preparation of C=C double bond-containing compounds from inexpensive starting materials is of great importance for organic synthetic chemistry. Here, we present a facile stereoselective P-mediated one-pot synthesis of unsymmetrically disubstituted E-alkenes from two different aldehydes.[1] The selectivity for the formation of E-alkenes is achieved by a sequential ionic mechanism. In the first step a phosphanylphosphonate[2] reagent 1 reacts with the first aldehyde to form a phosphaalkene intermediate 2 (Scheme 1). In this phosphaalkene the polarity of the carbonyl carbon has been reversed from δ+ to δ-, and the electrophilic phosphorus center in 2 can be activated by an alkoxide to afford intermediate 4. Oxidation of 4 leads to a phosphinate intermediate 5 which reacts under basic conditions with the second aldehyde to yield the olefinic product. By having electron withdrawing substituents R1 in the first aldehyde and electron donating groups as R2, E-stilbenes with a push-pull structural motif are easily accessible from simple aromatic aldehydes.[3]

Scheme 1: General reaction sequence for the reductive one-pot coupling. In comparison to the McMurry coupling[4], this new one-pot reaction proceeds under mild reaction conditions at room temperature and is free of transition metals. Moreover, it gives access to the formation of exclusively E-alkene products with an unsymmetrical substitution pattern in good overall yields.

References [1] K. Esfandiarfard, J. Mai, S. Ott, J. Am. Chem. Soc., 2017, 139, 2940-2943. [2] K. Esfandiarfard, A.I. Arkhypchuk, A. Orthaber, S. Ott, Dalton Trans. 2016, 45, 2201-2207. [3] J. Mai, S. Ott, manuscript in preparation. [4] J. E. McMurry, Chem. Rev. 1989, 89, 1513-1524.

Uppsala University, SWEDEN O24 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Computational study on substituted phosphorus ylides

Dániel Buzsáki, Tamara Teski, László Nyulászi

Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics H-1111 Budapest Szt. Gellert ter 4, Hungary e-mail: [email protected]

Phosphorus ylides are well-known as key intermediates in Wittig reactions.[1,2] To describe their bonding, two canonical structures were considered: the double-bonded ylide and the zwitterionic ylene [3] form (Scheme 1a). The ylides HX2P=CY2 generally rearrange to their isomer, the [4] thermodynamically more stable phosphane X2P–CY2H via proton shift. Accordingly, no H-ylides were able to form with the exception of some kinetically hindered cases.[5] However, the smallest ylide [4] (H3P=CH2) was detected in gas phase in high vacuum conditions, and its stability was explained by the high monomolecular isomeration barrier (34 kcal/mol).[2] The ylide can be relatively stabilized with respect to the phosphane by σ-donating and π-withdrawing substituents. The bonding and structural properties of substituted phosphorus ylides were deeply investigated theoretically with DFT methods. The thermodynamical stability of these compounds were determined in comparison to their phosphane isomers. Nevertheless, we could not find any HX2P=CY2 type of ylides which were more stable than its phosphane isomer. Furthermore, here we present the bimolecular mechanism, which can propose a low barrier alternative compared to the monomolecular mechanism, thus can explain the common isomerization of the ylide.

Scheme 1 a) Different canonical structures of the ylides, b) Considered proton transfer mechanisms in this work

Acknowledgement Financial support from NKFIH OTKA NN 113772, and the EU COST network CM 1302 “Smart Inorganic Polymers” is gratefully acknowledged.

References 1 G. Wittig, Science, 1980, 21, 500. 2 O. I. Kolodiazhnyi, Phosphorus ylides, WILEY-VCH Verlag, 1999. 3 H. J. Bestmann; A. J. Kos; K. Witzgall, P. v. R. Schleyer, J. Chem. Ber., 1986, 119, 1331. 4 H. Keck, W. Kuchen, P. Thommes, J. K. Terlouw, T. Wong, Angew. Chem., Int. Ed. Engl., 1992, 31, 86.. 5 a) S. Ekici, D. Gudat, M. Nieger, L. Nyulaszi, E. Niecke, Angew. Chemie Int. Ed., 2002, 41, 3367. b) S. Ito, H. Miyake, M. Yoshifuji, T. Höltzl, T. Veszprémi, Chem. Eur. J., 2005, 11, 5960.

Uppsala University, SWEDEN O25 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Phosphine-Free Wittig Reaction Using Umpolung at Phosphorus

Anna C. Vetter, Kirill Nikitin and Declan G. Gilheany*

School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland [email protected]

We have developed a new general Umpolung1 approach for the synthesis of quaternary phosphonium salts (QPS), whereby the new group, e.g. R1, is introduced using an organometallic reagent (R1-M). In our methodology, nucleophilic attrack on the electron-poor P(V) moiety replaces the traditional quaternization approach (see A).2 The new substitution is very fast and high-yielding (up to 106-times faster than direct quaternization of phosphine).

QPS are a key class of organophosphorus compounds essential for many areas of chemistry, for example for Wittig-type olefinations. Our new Umpolung approach to QPS is based on phosphine oxide (a by-product of the Wittig reaction) and avoids the use of direct quaternization of phosphines which often suffer from limited nucleophilicity and availability. In a neat example of a shortcoming becoming an opportunity, the phosphine oxide problem is eliminated as Wittig reactions can now be run phosphine-free (B). Moreover, this route allows access to entirely new phosphonium salts and phosphine oxide structures.

Acknowledgement The authors gratefully acknowledge the Synthesis and Solid State Pharmaceutical Centre for financial support (12/RC/2275). References

1 B.-T. Gröbel, D. Seebach, Synthesis 1977, 357-402 2 A. C. Vetter, K. Nikitin, D. G. Gilheany, submitted manuscript.

Uppsala University, SWEDEN O26 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis of Conformationally Constrained Aminomethylene gem- Bisphosphonic Acids

Rubén Oswaldo Argüello-Velasco,a Pawel Kafarski,a Mario Ordoñezb aDepartment of Bioorganic Chemistry, Faculty of Chemistry, Wrocław University of Science and Technology. Wroclaw. Poland. bCentro de Investigaciones Quimicas-IICBA, Universidad Autonoma del Estado de Morelos. Cuernavaca, Morelos. Mexico. [email protected]

Cyclic aminomethylene gem-bisphosphonic acids are considered as promising anticancer, antiinflammatory, antiparasitic, antiviral and antibacterial agents1, as they produce inhibitory effect towards a variety of enzymes. Despite acknowledged biological importance of acyclic aminomethylene gem-bisphosphonic acids, much remains to be explored about the synthesis and biological activity of their cyclic counterparts. Preliminar studies consider derivates of pyrrole oxides as a new class of spin traps.2 Thus, we have decided to study the reactivity of different cyclic amides, basing on the results described by Chmielewska and co-workers2. The reaction was carried out using the corresponding amide with (EtO)3P prompted by POCl3 to give the corresponding bisphosphonate, which upon hydrolysis with 6M HCl should yield desired acids (Figure 1). However, this reaction appeared quite complex yielding many unexpected products.

Figure 1 Acknowledgement The authors gratefully acknowledge the COST action by a statutory activity subsidy from the Polish Ministry of Science and Education for the Faculty of Chemistry of Wrocław University of Science and Technology References 1 a) Neville-Webbe, H. L.; Gnant, M.; Coleman, R. E. Semin. Oncol. 2010, 37, S53-S65. b) Toussirot, E.; Wendling, D. Curr. Opin. Rheumatol. 2007, 19, 340-345. C) Singh, A. P.; Zhang, Y.; No, J. H.; Docampo, R.; Nussenzweig, V.; Oldfield, E. Antimicrob. Agents Chemother. 2010, 54, 2987-2993. d) Agapkina, J.; Yanvarev, D.; Anisenko, A.; Korolev, S.; Vepsäläinen, J.; Kochetkov, S.; Gottikh, M. Eur. J. Med. Chem. 2014, 73, 73-82. e) Forlani, G.; Petrollino, D.; Fusetti, M.; Romanini, L.; Nocek, B.; Joachimiak, A.; Berlicki, Ł.; Kafarski, P. Amino Acids 2012, 42, 2283-2291. 2 Olive, G.; Le Moigne, F.; Mercier, A.; Rockenbauer, A.; Tordo, P. J. Org. Chem. 1998, 63, 9095-9099. 3 Chmielewska, E.; Miszczyk, P.; Kozlowska, J. Prokopowicz, M. Mlynarz, P. Kafarski, P. J. Organomet. Chem. 2015, 785, 84-91.

Uppsala University, SWEDEN O27 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Using silylphosphanes as ligands - synthetic and theoretical investigations of diphosphastannylenes

Elisabeth Schwarz,a Stefan Müller, Ana Torvisco and Michaela Flock*

aInstitute of Inorganic Chemistry, Graz University of Technology. Graz. Austria. @ [email protected]

The number of publications that examine α,α′ - nitrogen stabilized cyclic carbenes (NHC, Arduengo carbenes) is quite large given that there is just one analogous α,α′- phosphorus stabilized compound of this type[1]. Both, NHCs and their heavier analogous diaminotetrylenes, have, due to their high reactivity, substantial possibilities in transition metal catalysis. Although there is just one cyclic diphosphatetrylene several acyclic ones are known in literature. Most of these diphosphatetrylenes are either stabilized by intermolecular bases or via dimerization. Monomeric diphosphatetrylenes usually feature very bulky substituents for stabilization [2,3]. Izod[4] recently characterized monomeric diphosphastannylenes and –germylenes with large substituents that have one planar phosphorus centre which might aid the stabilisation. Using calculations at the DFT level together with exact cone angle calculations[5] we explored the stabilization effects of various phosphorus substituents (H, Me, tBu, Ph, TMS,

Hyp=(Si(SiMe3)3)) on diphosphastannylenes. Our synthetic work led to the isolation if two supermesityl(trimethylsily)phosphanides and the characterisation of a novel monomeric diphosphastannylene, [HypP(SiMe3)]2Sn.

R R

P P

R Sn R

R = H, Me, tBu, TMS, Hyp, Ph R’ = Mes*, Hyp Acknowledgement The authors gratefully acknowledge the COST action CM1302 (SIPs). References 1 D. Martin, A. Baceiredo, H. Gornitzka, W.W. Schoeller, G. Bertrand, Angewandte Chemie International Edition 2005, 44, 1700–1703. 2 M. Driess, R. Janoschek, H. Pritzkow, S. Rell, U. Winkler, Angew. Chem. Int. Ed., 1995, 1614. 3 T. Řezníček, L. Dostál, A. Růžička, R. Jambor, Eur. J. Inorg. Chem., 2012, 2983. 4 K. Izod, P. Evans, P.G. Waddell, M.R. Probert, Inorganic Chemistry, 2016, 10510–10522. 5 J.A. Bilbrey, A.H. Kazez, J. Locklin, W.D. Allen, J. Comput. Chem. 2013, 34, 1189–1197.

Uppsala University, SWEDEN O28